学习日记--vue 监听窗口宽度

步骤：
1.声明函数
2.mountde（） 中添加 上面的函数

newBodySize() {
                this.divWidth = document.body.clientWidth - 400;
                this.divHeight = document.querySelector('.mDivList').offsetHeight;
                this.divWidth2 = document.querySelector('.mDivList > div').offsetWidth;
                this.divHeight2 = document.querySelector('.mDivList > div').offsetHeight;
                this.divList();
 
                var that = this;
                window.onresize = function () {
                    // that.divWidth = document.querySelector('.mDivList').offsetWidth;
                    that.divWidth = document.body.clientWidth - 400;
                    // console.log(that.divWidth);
                    that.divList();
                }
            }
 
 
  mounted() {
            // this.divList();
            this.newBodySize();
        },